December 10, 2012

Ecological Fallacies

By Sally Raskoff

I’m one of those people who still reads the print newspaper.
Actually, I read three of them, and am periodically aware of how they present
the same news story in such different ways.
Sometimes it takes looking at a variety of different sources to see how
the presentation of a new research study can be misleading thanks to word
choice or conclusions that the reporter draws that the study itself actually
does not make.

The CDC noted that “Compared with 2008, the total
number and rate of reported abortions for 2009 decreased 5 percent,
representing the largest single year decrease for the entire period of analysis,”
and … “From 2000 to 2009, the total number, rate, and ratio of reported
abortions decreased 6 percent, 7 percent, and 8 percent, respectively, to the
lowest levels for 2000–2009.”

The
CDC report concludes that, based on many different studies, the reasons for the
drop include availability of abortion providers, various laws and regulations
(e.g., state regulations, parental involvement laws, legal restrictions on
abortion providers), increasing acceptance of non-marital childbearing, shifts
in the racial-ethnic population, economic changes, and last but not least,
fertility preferences and access to health care services such as contraception.

The Los
AngelesDaily News reported the
following:

“Abortions
fall in U.S.

Abortions fell 5 percent during the recession and
its aftermath. The decline may be due to women being more careful about birth
control during tough times.”

Nowhere in the CDC report did it mention that
women would be more “careful” during “tough times.” As noted above, the report
focused on larger-scale explanations based on the data available. For the rest
of the article, the Daily News stuck more closely to the conclusions cited
in the CDC report.

This type of suggestion makes a number of
assumptions about women without data for support, presuming more about birth
control than abortion. This statement is also a great example of a an ecological fallacy.

An ecological fallacy an error of logic that
occurs when you draw conclusions about individuals based on aggregate data.
When we have information on a large group of people, as we do here, we can’t
draw conclusions about personal choices individuals make. While we might
construct hypotheses about individual-level behavior, we would have to conduct
further research to know if indeed this is why abortion rates fell.

Note how the reasons mentioned by the CDC all
have to do with societal or structural issues, not with individuals or their decisions. Public policies have a major impact on
abortion rates. When state and federal policies about abortion change, we are
likely to see changes in abortion rates as access to this procedure change. Nowhere
does the CDC data indicate nor should we assume that women are careless about
birth control during good economic times and more careful during tough times.

It’s tempting to think about individual
explanations for social changes, in large part because many of us are
unaccustomed to thinking about social structure, a
key component of any sociological imagination. Although abortion is very
controversial and it may be tempting to create our own hypotheses explaining
why rates rise or fall, it is vital to base any of these conclusions on data
and not assumptions.

What other ecological fallacies can you think of
that attempt to explain large-scale phenomena with small-scale explanations?